I agree the RTC Ack is sent from RNC - also we see RTC Acquired and FTC Desired very quickly so the reverse link is in good condition - it leaves 3 choices: - DOM doesn't send RTC Ack (we have seen this before but usually because AT doesn't request a non-0 DRC rate) - lost over the air - seems unlikely - RTC Ack is lost in the DOM Did you change the DOM? Other than that I don't know what to suggest but it certainly looks like an equipment fault. Also, from your questions: - EpNo is only available on Idle state Route Updates - ChanInc is only available when the channel number is data-filled in the neighbor list (not required except in special circumstances) ... so these are both normal. Regards...

=================================== Martin KENDALL

Hi Martin, Today, we've got the RNC log based on the instruction. From the log, system has sent out this message : Tx to AT : RTC Ack Message, but the AT didn't receive it, so this message missing from the drive test log. For the message below, not clear why all the access failure with EpNo NotAvailable?02-12-2007 16:47:30.028 Route Update Detail : Seq # 1 : State Connected : PN 87 : Phase 0 : IP 10.16.193.241 : Strength -1dB : Keep Y : EpNo NotAvailable : ChanInc NotAvailable 0x002A0925 66305 418  Pls see the log RNC and drive test log attached, thanks for your help. CheersYe Shengfang 

Hi,See attached for some info on RNC logs: Regards...

=================================== Martin KENDALL

 Hi Martin, Pls see the RNC log and the drive test data for the EVDO site. I meet some problem to process the RNC log using NEWTUN. Do you have any comments about the RNC log(what attribute should be included in the RNC log or procedure for collecting the log)?thanks.

  CheersYe Shengfang 

OK, if changing the DOM doesn't help, next step would be to get RNC logs and I can look at those if you need. I notice you are on release 2.2 - are you planning to upgrade soon? Regards... 

 Hi Martin, From the drive test log, the EVDO call is 100% access failure for all the 3 sectors even we did the test just under the sector's antenna (no more than 50 meters far away from the sites). The two parameters at the DOM as below:Timing Advance is 86 (same datafill as other site in the same RNC)Reverse Distribution Delay is 44. Pls see the attached datafill for all the sites in the system, Tomorrow we'll try to change a new DOM for this site. CheersYe Shengfang 

So, what I see is the Ac Ack and Traffic Channel Assignment seem quite reliable so the control channel stage is good. The RTC Ack would indicate that the reverse traffic channel has been acquired so that is the step that is failing. I do see the Traffic Channel Valid bit in the Quick Config message get set so the traffic channel has been setup on the correct sector (no IP datafill wrong). For the calls that fail vs. those that succeed, is there any dependence on distance from the site? Can you check the following values at the DOM:Timing Advance (should be around 60 to 80 range)Reverse Distribution Delay (should be around 40 to 60 range) Regards...

===================================

Hi Martin,

We are pretty green as far as EVDO performance issues. The site being tested exhibits close to 100% AFs. Attached is a drive test (no RNC log). Can you take a look and suggest possible causes or next steps to identify the root cause?

Cheers,

Chris Jedrzycki Mobile: +84 90 604 8530 Tel: (84) 4 577 3628 (ESN 624 3628)

Hi Chris, Pls see the drive test data attached, RTCAck message is missing for all the EVDO access failure attempts. =======================Ye Shengfang